Oahu is losing its tree cover, and that is bad news for residents facing higher cooling bills, worse flooding, and hotter neighborhoods.

• Honolulu's tree canopy started shrinking a decade ago, mostly from neglect rather than storms or fires.
• Months of severe weather have knocked down trees and branches, and another storm is on the way.
• Trees cool the air, cut energy costs, clean pollution, soak up floodwater, block wind, and raise property values.
• Most trees in urban Honolulu sit on private land, so owners need an incentive like a tax credit to maintain them.
• Even the city's own share is split across 23 separate agencies, and replanting is slowed by a shortage of native seeds.

Outlook: Replacing the canopy will take decades, so the near-term focus is better coordination, incentives for private owners, and planting a mix of native trees.